Implement SSE instructions

kernel/amd64/proc.h

@@ -2,6 +2,7 @@
 #define _KERNEL_AMD64_PROC_H
 
 #include <amd64/intr.h>
+#include <aux/compiler.h>
 #include <libk/std.h>
 
 /* Top of userspace process' stack */
@@ -17,6 +18,7 @@ struct proc_platformdata {
   uintptr_t kernel_stack;
   uint64_t fs_base;
   uintptr_t tls_vaddr;
+  uint8_t fx_env[512] ALIGNED (16);
 };
 
 #endif // _KERNEL_AMD64_PROC_H